1. Field of the Invention
The present invention relates to a rotating electrical machine with a stator cooled with a cooling medium.
2. Description of Related Art
The standard procedures through which a stator of a rotating electrical machine that drives an electric vehicle is cooled include an oil cooling method whereby an ATF (automatic transmission fluid) in the transmission is directly sprayed onto winding portions (coil end portions) exposed at ends located along the rotational axis of the rotating electrical machine.
As an alternative to the method whereby the cooling medium is directly sprayed onto the winding, there is a method known in the related art whereby the stator is cooled with a cooling medium delivered into a slot (see, for instance, Japanese Laid Open Patent Publication No. 2005-168265). Such a cooling system adopts a structure that includes a pipe in each slot housing the stator winding, in which the cooling medium flows in the pipe, and the cooling medium is allowed to flow out through holes formed on the surface of the pipe.